Embodiments relate to an electric vehicle, and more particularly, to a switching device for an electric vehicle and a method of controlling the switching device.
Alternative energy vehicles include electric vehicles (EVs), hybrid electric vehicles (HEVs) using both fossil fuel and electrical energy, and fuel cell electric vehicles (FCEVs).
Electric vehicles receive power from a battery, and include a motor control device such as an inverter to control a motor, thereby achieving optimal efficiency. Furthermore, since a motor of electric vehicles replaces an engine, electric vehicles are truly eco-friendly vehicles without the emission of poisonous gas.
FIG. 1 is a circuit diagram illustrating a driving system for a typical electric vehicle as described above.
Referring to FIG. 1, an electric vehicle 100 includes a battery 110, an inverter 120, a motor 130, and a controller 140.
The electric vehicle 100 is driven by direct-current (DC) power supplied from the battery 110. The inverter 120 converts the DC power into three-phase alternating current (AC) power for driving the motor 130.
The controller 140 controls the inverter 120 by using a pulse width modulation (PWM) control method for converting DC power into AC power. A gate signal generated from the controller 140 includes a PWM switching signal for controlling the inverter 120.
However, there is a limit for power stored in the battery 110 to drive the motor 130. When the battery 110 is discharged to under a certain power level, the battery 110 cannot drive the motor 130.
Thus, the electric vehicle 100 requires a high voltage charger to charge the battery 110 with high power. Such high voltage chargers may be classified into low speed chargers using single phase power for home use; and high speed chargers using three-phase power for transmitting/supplying electricity.
However, in the related art, an inverter, a high voltage charger, and a low voltage charger are individually manufactured and installed. Thus, overlapping parts inefficiently increase the cost, volume and weight of a vehicle. That is, an inverter uses a power semiconductor switch for driving a motor, and a charger uses a power semiconductor switch for charging.
To address this issue, an inverter and a charger are integrated, and thus, semiconductor switches used therein are also integrated, thereby decreasing the number of inductors that would be otherwise used in the semiconductor switches.
However, when power semiconductor switches having different functions are integrated into a single power semiconductor switch, the single power semiconductor switch should process a plurality of signals. In addition, a plurality of signals may overlap one another or collide with one another during a series of processes.